Frieren is not dense, she lacks the understanding of interpersonal relationships, remember that after her master died she lived in isolation until Himmel recruited her, even as an elf a milenia alone surely took a tool in Frieren mental development, more if we remember she was a child at the time
Maybe not a boyfriend, but I want to see her getting a male friend.
Who knows? Maybe that boy that can draw, so she develops an story and he draw it and they becomes pros ... wait a moment, so after all watamote is truly an autobiography .